Performance Analysis of Chebyshev UWB Bandpass Filter Using Defected Ground Structure

This paper deals with design and analysis of chebyshev ultra-wideband (UWB) bandpass filter with wide passband using defected ground structure. The BPF is constructed from the step impedance lowpass filter (LPF), optimum distributed highpass filter (HPF) and four rectangular shaped DGS were etched on the ground plane. Furthermore, the LPF and HPF are designed, based on their equivalent L-C circuit on Electromagnetic (EM) Circuit Simulator. The calculation of lumped element values is done and performance analysis curves are plotted for these filters which are compared to their practical response as done on CST. The analysis on Electromagnetic (EM) Circuit Simulator is done for UWB here, but the same can be done for any general frequency band on microwave range. Further, a compact UWB bandpass filter is designed on FR-4 substrate of thickness h = 1 mm with Dielectric constant = 4.05 is and it occupies 22.4mm x 12mm die of area. The working frequency of UWB filter is 3.1 to 10.6 GHz. The design of this filter is simulated on CST Microwave studio showing the desired simulation response.